GB1071729A - Improvements in or relating to a.c. attenuators - Google Patents

Improvements in or relating to a.c. attenuators

Info

Publication number
GB1071729A
GB1071729A GB46174/65A GB4617465A GB1071729A GB 1071729 A GB1071729 A GB 1071729A GB 46174/65 A GB46174/65 A GB 46174/65A GB 4617465 A GB4617465 A GB 4617465A GB 1071729 A GB1071729 A GB 1071729A
Authority
GB
United Kingdom
Prior art keywords
pilot
control
windings
transformer
signal
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
GB46174/65A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Ampex Corp
Original Assignee
Ampex Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Ampex Corp filed Critical Ampex Corp
Publication of GB1071729A publication Critical patent/GB1071729A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03G—CONTROL OF AMPLIFICATION
    • H03G3/00—Gain control in amplifiers or frequency changers
    • H03G3/20—Automatic control
    • H03G3/30—Automatic control in amplifiers having semiconductor devices
    • H03G3/3005—Automatic control in amplifiers having semiconductor devices in amplifiers suitable for low-frequencies, e.g. audio amplifiers
    • H03G3/301—Automatic control in amplifiers having semiconductor devices in amplifiers suitable for low-frequencies, e.g. audio amplifiers the gain being continuously variable
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F19/00—Fixed transformers or mutual inductances of the signal type
    • H01F19/04—Transformers or mutual inductances suitable for handling frequencies considerably beyond the audio range
    • H01F19/06—Broad-band transformers, e.g. suitable for handling frequencies well down into the audio range
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F29/00—Variable transformers or inductances not covered by group H01F21/00
    • H01F29/14—Variable transformers or inductances not covered by group H01F21/00 with variable magnetic bias
    • H01F29/146—Constructional details
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03G—CONTROL OF AMPLIFICATION
    • H03G1/00—Details of arrangements for controlling amplification
    • H03G1/0005—Circuits characterised by the type of controlling devices operated by a controlling current or voltage signal
    • H03G1/0035—Circuits characterised by the type of controlling devices operated by a controlling current or voltage signal using continuously variable impedance elements
    • H03G1/0076—Circuits characterised by the type of controlling devices operated by a controlling current or voltage signal using continuously variable impedance elements using galvanomagnetic elements
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03G—CONTROL OF AMPLIFICATION
    • H03G1/00—Details of arrangements for controlling amplification
    • H03G1/02—Remote control of amplification, tone or bandwidth

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Multimedia (AREA)
  • Digital Transmission Methods That Use Modulated Carrier Waves (AREA)
  • Transmitters (AREA)
  • Networks Using Active Elements (AREA)

Abstract

1,071,729. Transformers. AMPEX COPORATION. Nov. 1, 1965 [Nov. 4, 1964], No. 46174/65. Heading H1T. [Also in Divisions H3 and H4] A variable permeability transformer (A.C. attenuator) comprises a core 1 (Fig. 2) of a ferrite whose hysteresis loop is of minimal squareness and area provided with D.C. control (bias) windings 30 wound through slots in opposing legs of the core 1 so that each pair of windings 30, 30<SP>1</SP> and 30<SP>11</SP>, 30<SP>111</SP> forms a flux path 26 encircling the slots in opposed directions, these flux paths 26 being shorter than the main flux path 16 linking primary and secondary windings 10, 20. Automatic gain control.-In a closed loop automatic gain control system (Fig. 4, not shown), the input signal (e.g. FM with sidebands) may be mixed with a pilot and applied to the input terminal (12) of the transformer (1). At the transformer output (22) the pilot may be separated from the signal to be controlled by a pilot eliminator (40) and pilot extractor (42), a detector (44) rectifies and smooths the pilot signal to remove the carrier, and the remaining carrier error signal may be used by a control driver (46) to vary the control current in the control windings (30) about the level set by the D.C. bias supply (36) and potentiometer (38). In an open loop automatic gain control system (Fig. 5, not shown) the pilot extractor (42) may be connected to input terminal (12) of the transformer (1) although the eliminator (40) may remain in the transformer output circuitry. A non-linear amplifier (48) is connected between the detector (44) and control driver (46) to compensate for non-linear characteristics in the system, and D.C. biasing of the control windings (30) may be effected as before.
GB46174/65A 1964-11-04 1965-11-01 Improvements in or relating to a.c. attenuators Expired GB1071729A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US408839A US3359511A (en) 1964-11-04 1964-11-04 Automatic gain control system with pilot signal

Publications (1)

Publication Number Publication Date
GB1071729A true GB1071729A (en) 1967-06-14

Family

ID=23617988

Family Applications (1)

Application Number Title Priority Date Filing Date
GB46174/65A Expired GB1071729A (en) 1964-11-04 1965-11-01 Improvements in or relating to a.c. attenuators

Country Status (6)

Country Link
US (1) US3359511A (en)
BE (1) BE671791A (en)
DE (1) DE1288640B (en)
FR (1) FR1454661A (en)
GB (1) GB1071729A (en)
NL (1) NL6514180A (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3772617A (en) * 1972-11-02 1973-11-13 Bell Telephone Labor Inc Method and arrangement for setting the remanent flux density in magnetic circuits and equalizer utilizing same
US11502614B2 (en) 2020-01-15 2022-11-15 Raytheon Company Magnetic components with electrically variable characteristics
EP4322405A1 (en) * 2022-08-11 2024-02-14 Nxp B.V. Tunable attenuator

Family Cites Families (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE892304C (en) * 1940-04-06 1953-10-05 Aeg Single-phase transformer or choke
US2519426A (en) * 1948-02-26 1950-08-22 Bell Telephone Labor Inc Alternating current control device
BE505025A (en) * 1950-08-02
GB693255A (en) * 1951-04-12 1953-06-24 Automatic Telephone & Elect Improvements in or relating to carrier current transmission systems
US2683777A (en) * 1952-03-27 1954-07-13 Bell Telephone Labor Inc Automatic control of amplification in long distance transmission systems
GB750519A (en) * 1953-09-10 1956-06-20 British Telecomm Res Ltd Improvements in automatic control devices for use in telecommunication systems
US2974224A (en) * 1956-08-28 1961-03-07 Gilfillan Bros Inc Apparatus for automatic gain control
US2804583A (en) * 1956-10-18 1957-08-27 Gen Electric Direct current motor speed control system
US2938180A (en) * 1956-10-25 1960-05-24 Witz Gerhard H De Use of electrically controllable variable inductor for tuning purposes
DE1122580B (en) * 1957-05-31 1962-01-25 Siemens Ag Low frequency transmitter with a transfluxor core, especially for railway safety
US3204177A (en) * 1961-11-02 1965-08-31 Michel Adolf Keying devices, particularly for electrical musical instruments
US3242419A (en) * 1963-01-03 1966-03-22 Ben R Walburn Variable voltage transformer system

Also Published As

Publication number Publication date
NL6514180A (en) 1966-05-05
DE1288640B (en) 1969-02-06
US3359511A (en) 1967-12-19
FR1454661A (en) 1966-02-11
BE671791A (en) 1966-03-01

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